A new study from the University of Miami has found that high sound levels from Ultra Music Festival 2019 caused “a significant stress response” in fish swimming in waters near the EDM festival's site, similar to the stress levels that they would experience if they were being chased by a predator. Following the study’s release, Ultra announced that it is seeking a new South Florida location.

The University of Miami’s Rosenstiel School of Marine and Atmospheric Science has an experimental hatchery and research operations on Virginia Key, the barrier island near Miami where Ultra was held this past year. During the festival, which took place in March, they conducted tests on toadfish at the hatchery and also monitored decibel levels in their tanks and the surrounding waters. On May 6, the university issued their first official findings, stating that the high volume levels caused toadfish to experience a “4-to-5-fold increase in blood cortisol, their main stress hormone, during the first night of the Ultra Music Festival.”

“The stress response was higher than what would be experienced when being chased by a simulated predator and similar to when hearing bottlenose dolphins, a toadfish predator,” said Danielle McDonald, professor of marine biology and ecology at the UM Rosenstiel School, in a statement.

Hydrophone recordings revealed a 7-9 decibel increase in the toadfish tanks and a 2-3 decibel increase in the low frequency range in Bear Cut, the channel that runs between Virginia Key and neighboring Key Biscayne. “Variations in the sonic activity of marine organisms and additional noise from boat traffic may have contributed to the signal detected in Bear Cut during Ultra,” said Claire Paris, professor of ocean sciences. Paris states that more studies are necessary to gauge the potential long-term impact Ultra has had on the wild fish population in the Virginia Key area.

In the wake of the festival, humans made noise complaints as well. Speaking to CBS Miami in early April, Mayor Francis Suarez voiced concerns about how loud the music at Ultra was. “I let the organizers know before the event, I let them know during the event, and I’m certainly going to let them know after the event that low frequency bass penetrating miles into the city is not acceptable,” he said at the time. “I live seven miles away and I could hear it at my house. It’s something that’s a big problem and it’s something that’s non-negotiable for me.”

The University of Miami researchers made their concerns regarding the effect of high volume levels on nearby fish populations known as early as November 2018. At the time, festival organizers stated that they would work alongside environmental regulators and that loud music would not reach the toadfish tanks, as the Miami Herald reports. According to Key News, preliminary findings from the study were presented to the local Virginia Key Advisory Board last month. The board has since formally objected to Ultra being held on Virginia Key again in 2020.

The University of Miami findings are not the only reason that citizens of Virginia Key and Key Biscayne are protesting the return of Ultra to their area. During an April 11 advisory board meeting, Key Biscayne Mayor Michael Davey objected to the festival’s license being renewed for 2020, citing noise complaints, garbage issues, and most notably transportation infrastructure problems that plagued the 2019 edition of the festival.

Severe congestion held up a planned fleet of 200 buses, which were supposed to shuttle festival-goers back to Miami after the first night of the festival. This resulted in many attendees walking nearly three miles back to Miami across the Rickenbacker Causeway. “Obviously the first day we had some hiccups if you will with our transportation plan,” Ultra head of security Ray Martinez told CBS Miami in April. “We made adjustments as we moved forward and I can tell you Sunday night it worked flawlessly.”

The Miami City Commission was set to review Ultra’s license agreement with the city tomorrow.

This article was originally published on Wednesday, May 8 at 3:31 p.m. Eastern. It was last updated on May 8 at 7:07 p.m. Eastern.